Europe's seven spot ladybug recovers from Asian 'attack'

As is so often the case, things started to go wrong when humans got involved.

The East Asian beetle, Harmonia axyridis, was introduced to parts of North America and Europe as a means to control pests such as aphids - but it has since spread, almost uncontrollably, and become a problem in itself.

Otherwise known as the harlequin ladybug, because of its many colors, Harmonia axyridis has become a grape pest and a threat to native biodiversity.

It has also threatened the existence of Europe's most common - and much loved - ladybug, the seven spot, Coccinella septempunctata.

Experts say the first evidence of Harmonia axyridis in Germany is from 2002. Within two years, it was virtually the only ladybug you could find.

Recovery

But the seven spot ladybug has made a comeback - and it appears to be in rude health in Germany.

"The seven spot ladybug is saved," says Werner Schulze of the Nature and Biodiversity Conservation Union. "It seems to have survived the attack."

And its future is looking good, too.

In a study using climatic chambers, researchers at the Julius Kühn Institute in Kleinmachnow found the Coccinella septempunctata had healthier prospects than its Asian competitor.

"We found that under raised temperatures, our native seven spot ladybug eats more than under current, normal temperatures," says the institute's Sandra Krengel. "The Harmonia axyridis also eats more, but its body weight and solid body content stagnate."

The researchers say their study suggests rising temperatures due to climate change will not necessarily favor the Asian beetle.

Not so lucky

The two spot ladybug, Adalia bipunctata, meanwhile, is not so lucky.

It was once more common in Europe and North America than the seven spot ladybug, but it has become very rare.